during super bowl. jessica kartalija reports, energy officials are taking the blame for this major mistake. jess? >> reporter: well, kai, ironically, the system was designed to prevent something like this from happening in power outage. but it turned out to be defective itself. >> reporter: seconds into third quarter of the super bowl. >> half the power in new orleans stadium, the super dome here, is out. >> reporter: the super dome's power company, entergy, taking the blame, saying a device, known as a relay in the company's switch gear malfunctioned. cutting power to one of two feeder lines, supplying power to the dome. >> it's important to find the root cause. and it's now been traced back to this relay, this faulty device, inside that switch gear that entergy owns. and i think that can be fixed. >> reporter: the super dome was dimly lit for 34 minutes, while crews worked to restore power. >> that means about a 20-minute delay. >> reporter: ravens' head coach, john harbaugh, appearing on david letterman thursday, jokes about the outage. >>